Optical module

ABSTRACT

An optical module includes: a housing, a heat sink arranged in the housing, a laser emitter arranged on the heat sink, a PCB partially arranged on the heat sink, and an optical system arranged in the housing. The optical module has an optical interface on one end and an electrical interface on the other end. The optical system is arranged between the laser emitter and the optical interface. The PCB is constructed as a rigid board. The laser emitter is electrically connected to the PCB. One end of the PCB is fixed on the heat sink, and the other end of the PCB is constructed as the electrical interface. The optical system transmits light emitted from the laser emitter to the optical interface.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 16/024,963,filed Jul. 2, 2018 (allowed), which is based upon and claims priority toChinese Patent Application 201710591788.1, filed on Jul. 19, 2017, theentire content of all of which are incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates to the field of optical communicationtechnology and, more particularly, to an optical module.

BACKGROUND

With the development of society, the amount of data is increasing. Thisrequires that optical communication modules transmit data at a fasterspeed and cost less. Existing 3G technology is unable to meet thecomplex needs of users and markets. TD-LTE (Time Division-Long TermEvolution, long-term evolution of TD-SCDMA) has emerged as a technologythat paves the way from 3G to 4G. Due to the current shortage of opticalfiber resources, high cost of new installations, and relatively longdistances between base stations, the demand for small form-factorpluggable (SFP+) packaged optical modules has been gradually increasing.

Generally, in an optical module, electrical signals enter a PCBA(Printed Circuit Board Assembly) from gold contact fingers and are thenoutputted to an optoelectronic chip, which converts the electricalsignals into optical signals and output them to an optical port throughan optical system. The optical port and the electrical interface (goldcontact fingers) are both fixed relative to a housing of the opticalmodule. In general, the PCBA is rigid, the optical system is rigid, andall devices have certain dimensional tolerances.

Most optical module packaging technologies now use a flexible circuitboard (FPC) to absorb assembly tolerances. But the solder joints betweenthe flexible circuit board and the PCBA introduce relatively largeelectrical signal attenuation. Therefore, such optical module packagingtechnologies can only be used for transmission rates below 10G.

With higher transmission rates, the design of optical modules forlong-distance transmission requires smaller attenuation of high-speedelectrical signals. At the same time, to meet the assembly requirementsof the optical module, it is necessary to assemble the gold contactfingers, PCBA, optoelectronic chip, free-space optical path assembly,and optical port. Thus, a problem that needs to be resolved is how tointegrate the design for best conversion between and transmission ofoptical and electrical signals.

SUMMARY

A purpose of the present disclosure is to provide an optical module,which enables better transmission of high-speed signals.

Consistent with the aforementioned purpose, the present disclosureprovides an optical module, which includes a housing, a heat sinkarranged in the housing, a laser emitter arranged on the heat sink, aPCB partially arranged on the heat sink, and an optical system arrangedin the housing. The optical module has an optical interface on one endand an electrical interface on the other end. The optical system isarranged between the laser emitter and the optical interface. The PCB isconstructed as a rigid board. The laser is electrically connected to thePCB. One end of the PCB is fixed on the heat sink, and the other end ofthe PCB is constructed as the electrical interface. The optical systemtransmits light emitted from the laser to the optical interface.

The optical module further includes an assembly tolerance absorbingassembly arranged at the optical interface. The assembly toleranceabsorbing assembly transmits light emitted from the laser emitterthrough the optical system to a center of the optical interface or to anexternal connector connected to the optical module. Or the assemblytolerance absorbing assembly transmits light emitted from the laseremitter to the optical system.

The assembly tolerance absorbing assembly includes an optical element.The optical element is arranged between the optical system and theoptical interface or between the optical system and the laser emitter.The optical element is used for realizing a connection of an opticalpath between the optical system and the optical interface or of anoptical path between the optical system and the laser emitter.

The assembly tolerance absorbing assembly comprises an optical fiberthat connects between the laser emitter and the optical system. Theoptical fiber transmits light emitted from the laser emitter to theoptical system.

The heat sink includes a first heat sink and a second heat sink. Theoptical system is arranged on the first heat sink. The laser emitter ispackaged on the second heat sink. An optical fiber fixing element isarranged on each of the first heat sink and the second heat sink.

The assembly tolerance absorbing assembly includes a connecting port andat least one optical fiber that optically connects the connecting portand the optical interface. The connecting port is fixed on the heat sinkand is located between the optical system and the optical interface. Theoptical fiber transmits light emitted from the optical system to theoptical interface.

The assembly tolerance absorbing assembly includes an adapter that isseparately configured from the housing. The adapter is mated to theoptical interface. After the adapter and the housing are adjusted intoposition, they are fixed together by means of glue, screw tightening, orsoldering.

The optical system, optical interface, and circuit board are all fixedto the heat sink.

The adapter is connected to the housing along a direction parallel to aplugging direction of the optical interface. A gap for adjustment existsbetween the adapter and the housing in all directions perpendicular tothe plugging direction.

The optical module further includes a driver that is used to drive thelaser. The driver is packaged on the heat sink or the PCB.

The PCB is fixed to the heat sink by means of glue.

The optical interface includes a transmitting-end optical interface anda receiving-end optical interface. Light emitted from said laser istransmitted to the transmitting-end optical interface through theoptical system. Optical signals received by the receiving-end opticalinterface is transmitted to the optical receiving end through theoptical system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a three-dimensional drawing of an optical module in a firstembodiment of the present disclosure;

FIG. 2 is a top view of the optical module in FIG. 1;

FIG. 3 is an A-A′ section view of the optical module in FIG. 2;

FIG. 4 is a three-dimensional exploded view of the optical module inFIG. 1.

FIG. 5 is a three-dimensional drawing of an optical module in a secondembodiment of the present disclosure;

FIG. 6 is a top view of the optical module in FIG. 5;

FIG. 7 is a three-dimensional drawing of an optical module in a thirdembodiment of the present disclosure;

FIG. 8 is a three-dimensional exploded view of the optical module inFIG. 7.

FIG. 9 is a front view of an optical module in a fourth embodiment ofthe present disclosure;

FIG. 10 is a top view of the optical module in FIG. 9;

FIG. 11 is an enlarged view of the area “a” of the optical module inFIG. 10;

FIG. 12 is a three-dimensional diagram of an optical module in a fifthembodiment of the present disclosure;

FIG. 13 is a three-dimensional exploded diagram of the optical module inFIG. 12;

FIG. 14 is a front view of the optical module in FIG. 12; and

FIG. 15 is a B-B′ section view of the optical module in FIG. 14.

DETAILED DESCRIPTION

The text below provides detailed descriptions of the present disclosurethrough referencing specific embodiments as illustrated in the attacheddrawings. However, these embodiments do not limit the presentdisclosure; the scope of protection for the present disclosure coverschanges made to the structure, method, or function by persons ofordinary skill in the art on the basis of these embodiments.

FIG. 1 is a three-dimensional drawing of an optical module 100 in afirst embodiment of the present disclosure. FIG. 2 is a top view of theoptical module 100 in FIG. 1. FIG. 3 is a section view of the opticalmodule 100 along line A-A′ in FIG. 2. FIG. 4 is a three-dimensionalexploded view of the optical module 100 in FIG. 1. Referring to FIGS. 1through 4, in the first embodiment of the present disclosure, theoptical module 100 includes a housing 10 (only the lower part of thehousing is shown in the figures), a heat sink 20 arranged in the housing10, a laser emitter 31 arranged on the heat sink 20, and a PCB (printedcircuit board) 40 partially arranged on the heat sink 20. The opticalmodule 100 has an optical interface 42 on one end and an electricalinterface 43 on the other end. The optical interface 42 includes atransmitting-end optical interface 51 and a receiving-end opticalinterface 52. Here, the PCB 40 is constructed as a rigid board. One endof the PCB 40 is fixed on the heat sink 20 and is electrically connectedto the laser emitter 31, and the other end of the PCB 40 is constructedas the electrical interface 43 of the optical module. Here, gold contactfingers are arranged on the other end of the PCB 40, and the goldcontact fingers serve as the electrical interface 43 of the opticalmodule 100.

The optical module 100 further includes an optical system 60 that isarranged in the housing 10 and is located between the laser emitter 31and the optical interface 42. The optical system 60 may be at leastpartially arranged on the heat sink 20. A driver 35 of the laser emitter31 is packaged on the PCB 40. The laser emitter 31 may be packageddirectly on the heat sink 20, or it may be packaged on a pad of the heatsink 20. High-speed electrical signals are outputted from the driver 35to the PCB 40 and then outputted over a very short distance via a goldwire to the laser emitter 31. The optical system 60 transmits lightemitted from the laser emitter 31 to the optical interface 42. In otherwords, the laser emitter 31 at an optical transmitting end is opticallycoupled to the transmitting-end optical interface 51. Optical signalsreceived by the receiving-end optical interface 52 are transmittedthrough the optical system 60 to an optical receiving end, whichconverts the optical signals it receives into electrical signals. Inother words, the optical receiving end is optically coupled to thereceiving-end optical interface 52 and at the same time electricallyconnected to the PCB 40. In the entire high-speed link, there is noflexible board soldered so that signal loss caused by solder joints isreduced. In addition, the distance between the laser emitter 31 and thePCB 40 is short enough to ensure optimal electrical performance. And,using the heat sink 20 as a base, all elements are fixed to the heatsink 20 so assembly tolerances are small, and heat can be dissipated viathe heat sink 20, resulting in reliable performance and good heatdissipation.

The optical system 60 is arranged on one side of the laser emitter 31and includes a lens assembly and a wavelength division multiplexer. Thelens assembly includes at least one lens and is able to process, such asto focus or collimate, light emitted from the laser emitter 31 in orderto adjust the direction of propagation of the emergent light beam fromthe laser emitter 31, and the wavelength division multiplexor can mergea plurality of separate beams of light into one beam of light, so thatoptical signals emitted from the laser emitter 31 can be transmittedthrough the lens assembly and the wavelength division multiplexer to thetransmitting-end optical interface 51. The PCB 40 is horizontallyarranged inside the housing 10 of the optical module 100. The opticalreceiving end may be packaged directly on the heat sink 20 or bepackaged on a pad of the heat sink. Here, the laser emitter 31 includesa VCSEL (Vertical Cavity Surface Emitting Laser) chip, the opticalreceiving end includes a PD (photodiode) chip 32, and light transmittedfrom the receiving-end optical interface 52 passes through thewavelength division multiplexer and a reflective prism 33 before itreaches the PD chip 32. The VCSEL chip is soldered directly on the heatsink 20 and is electrically connected to the PCB 40 via a gold wire andis then electrically connected to the driver 35 packaged on the PCB 40.The PD chip 32 is also soldered directly on the heat sink 20. The laseremitter 31 may also include another type of laser chip. Similarly, theoptical receiving end may also include a PIN chip, an ADP chip, oranother detector chip. Additionally, the optical interface 42 may beconstructed as one interface, which is configured to be atransmitting-end optical interface, a receiving-end optical interface,or a two-in-one interface. In other words, the optical module 100 mayinclude a transceiving-end optical interface, which may be atransmitting-end optical interface, or a receiving-end opticalinterface, or both, or an integrated transceiving interface.

Further, in the first exemplary embodiment, the optical interface 42 isfixedly arranged relative to the housing 10, and the heat sink 20 isalso fixed relative to housing 10. In order that assembly tolerancesbetween the optical interface 42 and its corresponding laser emitter 31and/or an optical receiver, which is the optical receiving end discussedabove (here it is a photoelectric detector, i.e., the PD chip) can beabsorbed, the optical module 100 further includes an assembly toleranceabsorbing assembly 70, which is used to ensure that light emitted fromthe laser emitter 31 can be received by an external element connected tothe optical module 100 and that light emitted from the external elementconnected to the optical module 100 can be transmitted well to theoptical receiver. In other words, the assembly tolerance absorbingassembly 70 can transmit light emitted from the laser emitter 31 throughthe optical system 60 to a center of the optical interface 42 or to anexternal connector (not illustrated) connected to the optical module, orthe assembly tolerance absorbing assembly 70 can transmit light emittedfrom the laser emitter 31 to the optical system 60. Here, the center ofthe optical interface 42 is an approximate central place. The center ofthe optical interface 42 is the place where the external connectorreceives optical signals after the external connector is connected tothe optical module 100. The center of the optical interface 42 is alsothe place where the external connector transmits optical signals afterthe external connector is connected to the optical module 100. Theexternal connector includes an optical fiber plug, a switch interface,etc.

Specifically, the assembly tolerance absorbing assembly 70 is arrangedat the optical interface 42 and includes an optical element, which isarranged between the optical system 60 and the optical interface 42 andis used for realizing a connection of an optical path between theoptical system 60 and the optical interface 42. The optical elementincludes a transmitting-end optical element 71 and a receiving-endoptical element 72. The optical elements 71 and 72 may be lenses, plateglass, or reflective mirrors, or other elements that allow light to passthrough and change the light's direction of propagation. By adjustingthe optical path with these optical elements 71 and 72, light thatenters the transmitting-end optical interface 51 is caused to be locatedat the center of the transmitting-end optical interface 51 and lightthat enters the optical module 100 from the receiving-end opticalinterface 52 can reach the optical receiver well. Optical elements mayalso be arranged between the optical system 60 and the laser emitter 31and be used to connect the optical path between the optical system 60and the laser emitter 31.

The first embodiment further discloses an assembly method for theaforementioned optical module 100. The assembly method includes thefollowing steps: packaging the optical system 60, laser emitter 31, andthe PD chip 32 at the optical receiving end onto the heat sink 20;fixing one end of the PCB 40 on the heat sink 20; fixing the heat sink20 in the housing 10; and arranging the optical element 71 between theoptical system 60 and the optical interface 42, and adjusting theoptical element 71 so that the center of the optical path of the opticalinterface is aligned with the optical path of the laser emitter 31 andthe optical path of the PD chip 32 at the optical receiving end.

FIG. 5 is a three-dimensional drawing of an optical module 200 in asecond embodiment of the present disclosure. FIG. 6 is a top view of theoptical module 200 in FIG. 5. Referring to FIGS. 5 through 6, in thesecond embodiment of the present disclosure, the optical module 200similarly includes a housing 210, a heat sink 221/222 arranged in thehousing, a laser emitter 231 arranged on the heat sink, and a PCB 240partially arranged on the heat sink. The optical module 200 has anoptical interface 250 on one end and an electrical interface 243 on theother end. The optical interface 250 includes a transmitting-end opticalinterface 251 and a receiving-end optical interface 252. Here, the PCB240 is constructed as a rigid board. One end of the PCB 240 is fixed onthe heat sink 221/222 and is electrically connected to the laser emitter231, and the other end of the PCB 240 is constructed as the electricalinterface 243 of the optical module 200. Gold contact fingers forpluggable connection to an external part are arranged on the electricalinterface 243.

In the second embodiment, the heat sink 221/222 includes a first heatsink 221 and a second heat sink 222. An optical system 260 of theoptical module 200 is arranged on the first sink 221. The laser emitter231 and a PD chip 232 at an optical receiving end are packaged on thesecond heat sink 222. A driver 235 of the laser emitter 231 is packagedon the PCB 240. In the second embodiment, the optical interface 250 isfixedly arranged relative to the housing 210, and the first heat sink221 and the second heat sink 222 are also fixed relative to housing 210.In order that assembly tolerances between the optical interface 250 andits corresponding laser emitter 231 and/or an optical receiver can beabsorbed, an assembly tolerance absorbing assembly 270 of the opticalmodule 200 is arranged between the optical system 260 and the laseremitter 231/the PD chip 232 at the optical receiving end. Specifically,the assembly tolerance absorbing assembly 270 includes at least onetransmitting-end optical fiber 271 and at least one receiving-endoptical fiber 272. An optical fiber fixing element 273 is arranged oneach of the first heat sink 221 and the second heat sink 222, and thetwo ends of the optical fibers 271 and 272 are fixed by the opticalfiber fixing elements 273. By connecting an optical path using theoptical fibers 271 and 272, light emitted from the laser emitter 231 istransmitted to the optical system 260, or light received from theoptical system 260 is transmitted to the optical receiving end. Becausethe optical fibers 271 and 272 are soft and flexible, tolerance may beabsorbed by the optical fibers. In the second embodiment, the quantityof the optical fibers 271 and 272 is configured to be relevant to thestructure of the optical module 200 and to the transmission speed. Ifthe optical interface 250 of the optical module 200 is configured to bea single optical interface, then the quantity of corresponding opticalfiber may be configured to be one. When the transmission speedrequirement of the optical module 200 is relatively high, a plurality oflaser emitters may be configured for the optical module, and thequantity of the optical fibers 271 and 272 is consistent with thequantity of the laser emitters. Tolerance is absorbed by the arrangementof a soft and flexible optical fiber so that the center of the opticalpath of the optical interface 250 is aligned with the laser emitter 231at an optical transmitting end and the PD chip 232 at the opticalreceiving end.

The second exemplary embodiment further discloses an assembly method forthe aforementioned optical module 200. The assembly method includes thefollowing steps: packaging the optical system 260 onto the first heatsink 221; packaging the laser emitter 231 and the PD chip 232 at theoptical receiving end onto the second heat sink 222; fixing one end ofthe PCB 240 on the second heat sink 222; fixing both the first heat sink221 and the second heat sink 222 in the housing 210; and connecting anoptical fiber between the optical system 260 and the laser emitter 231and/or the PD chip 232 at the optical receiving end.

FIG. 7 is a three-dimensional drawing of an optical module 300 in athird embodiment of the present disclosure. FIG. 8 is athree-dimensional exploded view of the optical module 300 in FIG. 7.Referring to FIGS. 7 through 8, in the third embodiment of the presentdisclosure, the optical module 300 includes a housing 310, a heat sink320 arranged in the housing 310, a laser emitter 331 arranged on theheat sink, and a PCB 340 partially arranged on the heat sink 320. Theoptical module 300 has an optical interface 350 on one end and anelectrical interface 343 on the other end, and the optical interfaceincludes a transmitting-end optical interface 351 and a receiving-endoptical interface 352. Here, the PCB 340 is constructed as a rigidboard. One end of the PCB 340 is fixed on the heat sink 320 and iselectrically connected to the laser emitter 331, and the other end ofthe PCB 340 is constructed as the electrical interface 343 of theoptical module 300.

In the third embodiment, an optical system 360 of the optical module isarranged on the heat sink 320, a driver 335 of the laser emitter 331 ispackaged on the PCB 340, the laser emitter 331 is packaged on the heatsink 320, and a PD chip 332 at an optical receiving end is also packagedon the heat sink 320. The optical system 360 includes a transmittingoptical path and a receiving optical path. The transmitting optical pathincludes a wavelength division multiplexer, and the receiving opticalpath includes a wavelength division multiplexer and a reflective mirror.In the third embodiment, the optical interface 350 is fixedly arrangedrelative to the housing 310, and the heat sink 320 is also fixedrelative to housing 310. In order that assembly tolerances between theoptical interface 350 and its corresponding transmitting end and betweenthe optical interface 350 and its corresponding receiving end can beabsorbed, an assembly tolerance absorbing assembly of the optical moduleis arranged between the optical system 360 and the optical interface.Specifically, the assembly tolerance absorbing assembly includes aconnecting port 370 and at least one optical fiber that connects theconnecting port 370 and the optical interface 350. The connecting port370 is fixed on the heat sink 320. Here, the connecting port 370includes a transmitting connecting port 373 that corresponds to anoptical transmitting end and a receiving connecting port 374 thatcorresponds to the optical receiving end. Therefore, the quantity ofoptical fibers is configured to be two, and these two optical fibersare, respectively, a first optical fiber 371 that connects between thetransmitting-end optical interface 351 and the transmitting connectingport 373, and a second optical fiber 372 that connects between thereceiving-end optical interface 352 and the receiving connecting port374. The structure is made simple by using optical fibers 371 and 372 toconnect the optical path, and, if one optical interface is configured,only one optical fiber needs to be configured to meet the requirement,resulting in low cost.

The present example embodiment further discloses an assembly method forthe aforementioned optical module. The assembly method includes thefollowing steps: packaging the optical system 360, the laser emitter331, and the PD chip at the optical receiving end onto the heat sink320; fixing the connecting port 370 onto the heat sink 320; fixing oneend of the PCB 340 on the heat sink 320; fixing the heat sink 320 in thehousing 310; and connecting an optical fiber between the connecting port370 and the optical interface so that the center of the optical path ofthe optical interface is aligned with the optical path of thetransmitting end and the optical path of the receiving end through theoptical fiber.

FIG. 9 is a front view of an optical module 400 in a fourth embodimentof the present disclosure. FIG. 10 is a top view of the optical module400 in FIG. 9. FIG. 11 is an enlarged view of the area “a” of theoptical module 400 in FIG. 10. Referring to FIGS. 9 through 11, in thefourth embodiment of the present disclosure, an optical module 400similarly includes a housing 410, a heat sink 420 arranged in thehousing 410, a laser emitter 431 arranged on the heat sink 420, and aPCB 440 partially arranged on the heat sink 420. The optical module 400has an optical interface 450 on one end and an electrical interface 443on the other end. The optical interface 450 includes a transmitting-endoptical interface 451 and a receiving-end optical interface 452. Here,the PCB 440 is constructed as a rigid board. One end of the PCB 440 isfixed on the heat sink 420 and is electrically connected to the laseremitter 431, and the other end of the PCB 440 is constructed as theelectrical interface 443 of the optical module 400. In the fourthembodiment, an optical system 460 of the optical module 400 is arrangedon the heat sink 420. Both the laser emitter 431 and a driver 435 of thelaser emitter 431 are packaged on the heat sink 420. A PD chip 432 at anoptical receiving end is also packaged on the heat sink 420. Thedifference between the fourth embodiment and the first embodiment isthat the driver 435 of the laser emitter 431 is also arranged on theheat sink 420 and is connected to the laser emitter 431 via a gold wire,and, at the same time, the driver 435 is also located on the edge of thePCB 440 and is also connected to the PCB 440 via a gold wire. Theconfiguration of the other elements and components is essentially thesame as that in the first embodiment. No redundant description isrepeated in detail here.

FIG. 12 is a three-dimensional diagram of an optical module 500 in afifth embodiment of the present disclosure. FIG. 13 is athree-dimensional exploded diagram of the optical module 500 in FIG. 12.FIG. 14 is a front view of the optical module 500 in FIG. 12. FIG. 15 isa section view of the optical module 500 along line B-B′ in FIG. 14.Referring to FIGS. 12 through 15, in the fifth embodiment of the presentdisclosure, the optical module 500 includes a housing 510 and a PCB 540that is arranged in the housing. An accommodating space is arranged inthe housing 510, and the PCB 540 is arranged in the accommodating space.The PCB 540 may be snap-fitted to the housing 510. The PCB 540 may befixed to the housing 510 by screws. Alternatively, like in a previousembodiment, the PCB 540 has one end fixed on a heat sink and is thenfixed relative to the housing 510 via the heat sink. Stillalternatively, another connection method may be used. The PCB 540 may befully or partially accommodated in the accommodating space. An opticalinterface 550 is arranged on one end of the optical module, and anelectrical interface 543 is arranged on the other end of the opticalmodule 500. The end of the PCB 540 that is further away from the opticalinterface 550 is constructed as the electrical interface 543 of theoptical module 500.

Additionally, the optical module 500 further includes an assemblytolerance absorbing assembly that is connected to the housing. In thefifth exemplary embodiment, the assembly tolerance absorbing assembly isconstructed as an adapter 570. The adapter 570 is separately configuredfrom the housing 510, and at least a portion of the adapter 570 isaccommodated in the accommodating space. The optical module 500 furtherincludes an optical assembly 560 arranged on the PCB 540. The opticalassembly 560 has optical interfaces 551 and 552 that mate to the adapter570. A gap S between the adapter 570 and the housing 510 is adjustable.After the adapter 570 and the housing 510 are adjusted into position,they are fixed together by means of glue, screw tightening, orsoldering. The optical assembly 560 may be integrated onto the PCB 540as one piece, or it may be removably arranged on the PCB 540, or it maybe integrated onto a heat sink as one piece, that is, the opticalsystem, the optical interface, and the circuit board are all fixed tothe heat sink. Here, the optical assembly 560 is electrically connectedto the PCB 540.

In the fifth embodiment, the adapter 570 is separately configured fromthe housing 510, and the gap S between the adapter 570 and the housing510 is adjustable, preventing the problem of misalignment between theadapter 570 and the center of an optical path of the optical assembly560 caused by manufacturing tolerances of the adapter 570 and/or thehousing 510. In this way, the manufacturing tolerances between theadapter 570 and/or the housing 510 are converted into positiontolerances of the adapter 570, so that the adapter 570 can, according tothe position of the optical assembly 560, move relative to the housing510, making the optical assembly 560 and the adapter 570 of the opticalmodule 500 very easy to be plugged and unplugged and convenient toassemble.

When the optical assembly 560 is being plugged into the adapter 570, theplugging between the optical assembly 560 and the adapter 570 may bemanually controlled. A positioning fixture can be used in addition forpositioning in order to assemble the optical assembly 560 and theadapter 570 together.

Further, the optical assembly 560 is configured to include an opticalreceiving end, an optical transmitting end, and an optical system. Theoptical assembly 560 may also be configured to include a transceivingchip that integrates optical receiving and optical transmitting.

In the fifth exemplary embodiment, the optical assembly 560 isconfigured to have two optical interfaces. One of these interfaces is anoptical transmitting interface 551, and the other of these interfaces isan optical receiving interface 552. Alternatively, both interfaces maybe configured as optical transmitting interfaces or optical receivinginterfaces.

The gap S for adjustment exists between the end surfaces of the adapter570 that are parallel to the plugging direction of the opticalinterfaces 551 and 552 and the top, bottom, left, and right of thehousing 510. In this way, when assembling the adapter 570, the adapter570 may move in a plurality of directions including up, down, left, andright according to the position of the optical assembly 560.

In this example embodiment, the adapter 570 is fixed to the housing 510with dispensed glue in between. Other fixing methods may also be used.For example, the adapter 570 may be fixed to the housing 510 by threadedconnections in between.

The fifth exemplary embodiment further discloses an assembly method forthe aforementioned optical module 500. The assembly method includes thefollowing steps: assembling the optical assembly 560 and the PCB to thehousing 510; mating the adapter 570 to the optical interfaces 551 and552 of the optical assembly 560; and fixing the adapter 570 to thehousing 510. Dispensed glue may be used to fix the adapter 570 to thehousing 510 when fixing the adapter 570 to the housing 510. Other fixingmethods may also be used. For example, the adapter 570 may be fixed tothe housing 510 by threaded connections in between. When threadedconnection is used as the fixing method, spacers (not illustrated) ofcorresponding thickness may be placed in the gap S between the adapter570 and the housing 510 as required.

In other embodiments, the optical assembly 560 may be configured toinclude one optical interface. Correspondingly, a mating port existsbetween the adapter 570 and the optical assembly 560. In other words,the optical interface is configured to be an integrated transceivinginterface. The interface may also be configured to be an opticaltransmitting interface only or an optical receiving interface only.

It should be understood that despite the descriptions of embodiments inthe specification, each embodiment does not entail only one singleindependent technical solution. The specification is written this waysimply for the sake of clarity. Those skilled in the art should treatthe specification as a whole. The technical solutions associated withthe embodiments may be combined in appropriate ways to form otherembodiments that can be understood by persons of skill in the art.

The series of detailed descriptions above is only intended to providespecific descriptions of feasible embodiments of the present disclosure.The detailed descriptions are not to be construed as limiting the scopeof protection for the present disclosure; all equivalent embodiments orchanges that are not detached from the techniques of the presentdisclosure in essence should fall under the scope of protection of thepresent disclosure.

1-12. (canceled)
 13. An optical module, comprising: a housing; a heatsink disposed in the housing and thermally connected to the housing; anda printed circuit board (PCB) partially fixed to the heat sink, whereinthe optical module further comprises an optoelectronic chip electricallyconnected to the PCB and disposed on the heat sink, and the PCB is arigid printed circuit board, one end of the PCB being provided with agold finger for electrical connection to an external part.
 14. Theoptical module according to claim 13, wherein the optical module furthercomprises an optical interface at one end thereof and an assemblytolerance absorbing assembly disposed between the optoelectronic chipand the optical interface, and the assembly tolerance absorptionassembly affects light transmission between the optical interface andthe optoelectronic chip.
 15. The optical module according to claim 14,further comprising an optical system, the optical system being disposedbetween the assembly tolerance absorbing assembly and the optoelectronicchip or between the assembly tolerance absorbing assembly and theoptical interface.
 16. The optical module according to claim 15, whereinthe assembly tolerance absorbing assembly comprises a connecting portand at least one optical fiber optically connecting the connectingportion to the optical interface.
 17. The optical module according toclaim 16, wherein the connecting port is fixed on the heat sink andlocated between the optical system and the optical interface, and theoptical fiber transmits light emitted from the optical system to theoptical interface.
 18. The optical module according to claim 17, whereinthe other end of the PCB opposite to the gold finger is fixed to theheat sink by glue.
 19. The optical module according to claim 18, whereinthe optoelectronic chip and the PCB are electrically connected by a goldwire.
 20. The optical module according to claim 19, wherein theoptoelectronic chip comprises a first optoelectronic chip and a secondoptoelectronic chip, and both of the first optoelectronic chip and thesecond optoelectronic chip are disposed on the heat sink.
 21. Theoptical module according to claim 19, wherein the first optoelectronicchip is a laser emitter and the second optoelectronic chip is aphotodiode.
 22. The optical module according to claim 21, wherein thefirst optoelectronic chip is located at the end of the PCB near theoptical interface.
 23. The optical module according to claim 22, whereinthe optical system comprises a wavelength division multiplexer disposedon the heat sink, the connecting port comprises a transmittingconnecting port that corresponds to an optical transmitting end, and thetransmitting connecting port is connected to the optical interfacethrough an optical fiber.
 24. An optical module, comprising: a housing;a heat sink and a printed circuit board (PCB) disposed in the housing;an optoelectronic chip disposed on the heat sink; and an assemblytolerance absorbing assembly disposed in the housing, wherein one end ofthe optical module has an optical interface, the PCB is configured as arigid board, the assembly tolerance absorbing assembly is disposedbetween the optoelectronic chip and the optical interface, and theassembly tolerance absorbing component is configured to transmit lightbetween the optical interface and the optoelectronic chip.
 25. Theoptical module according to claim 24, wherein one end of the PCBopposite to the optical interface is provided with a gold finger as anelectrical interface of the optical module.
 26. The optical moduleaccording to claim 24, wherein the assembly tolerance absorbing assemblycomprises at least one optical fiber optically coupled between theoptical interface and the optoelectronic chip.
 27. The optical moduleaccording to claim 26, wherein the assembly tolerance absorbing assemblyfurther comprises a connecting port, the connecting port is fixed on theheat sink and connected to the at least one optical fiber, light emittedby the optoelectronic chip is transmitted to the optical interfacethrough the connecting port and the at least one optical fiber.
 28. Theoptical module according to claim 24, wherein the assembly toleranceabsorbing assembly comprises an adapter disposed separately from thehousing, and the adapter is mated with the optical interface.
 29. Theoptical module according to claim 28, wherein after the adapter and thehousing are adjusted in position, the adapter and the housing are fixedtogether by glue, screw tightening, or soldering.
 30. The optical moduleof claim 28, wherein a gap for adjustment exists between the adapter andthe housing in a direction perpendicular to a plugging direction. 31.The optical module according to claim 24, wherein the optical modulefurther comprises an optical system disposed between the opticalinterface and the optoelectronic chip.
 32. The optical module accordingto claim 31, wherein a portion of the PCB is fixed to the heat sink byglue.
 33. The optical module according to claim 31, wherein the opticalsystem is disposed between the assembly tolerance absorbing assembly andthe optoelectronic chip, and the optical system transmits lighttransmitted from the assembly tolerance absorbing assembly to theoptoelectronic chip.
 34. The optical module according to claim 33,wherein the optical system is disposed on the heat sink.
 35. The opticalmodule according to claim 33, wherein the optical system comprises alens assembly and a wavelength division multiplexer, the connecting portcomprises a transmitting connecting port corresponding to an opticaltransmitting end, and the transmitting connecting port and the opticalinterfaces are connected by an optical fiber.
 36. The optical moduleaccording to claim 24, wherein the optoelectronic chip comprises a laseremitter and a photodiode chip.
 37. The optical module according to claim36, wherein the optoelectronic chip and the PCB are electricallyconnected by a gold wire.